Supramolecular Structures and Morphology

The effects of supramolecular structure and morphology on electroluminescence of polymers have been investigated by means of novel ternary and binary rod-coil copolymers. Rod-coil-rod ternary copolymers with two differing rod components were shown to exhibit Forster-type excited state energy transfer, resulting in... 

Jenekhe and coworkers investigated the effect of supramolecular structure and morphology on the photophysical properties in polymer systems. For this purpose, they used rod-coil di- and triblock copolymers and polymer blend systems. 

Figure35 (a) Model of the supramolecular structure and morphology of the rod-coll copolymers by Jenekhe and Osahenl. (b) Shows the photoluminescence spectrum of poly(benzob/sthlazole-1,4-phenylene) and copolymers 1-100% PBZT 2-40% 3-20% 4-5%, (Reprinted from S.A. Jenekhe and J.A. Osahenl. Chem. Mater. 6 1906, 1994. Copyright [1994] American Chemical Society, With permission.)...

Figure 30 (a) Model of the supramolecular structure and morphology of the rod-coil... 

Amorphous Polymer - Amorphous polymers are polymers having noncrystalline or amorphous supramolecular structure or morphology. Amorphous polymers may have some molecular order but usually are substantially less ordered than crystalline polymers and, subsequently, have inferior mechanical properties. 

Fig. 28 (a) Chemical structure of a poly(THF)-BTP polyurethane, (b) Schematic representation of structure and morphology of the metallo-supramolecular polymer network formed by combination of poly(THF)-BTP and Zn. (c) Pictures of a film of the metallo-supramolecular polymer network made from poly(THF)-BTP and Eu before and after stretching. Adapted with permission from [95]. Copyright 2013 The Royal Society of Chemistry... 

Gun ko, V.M., Zarko, V.L, Turov, V.V. et al. 2010e. Regularities in the behaviour of nanooxides in different media affected hy surface structure and morphology of particles. In Shpak, A.P. and Gorbyk, P.P. (Eds.) Nanomaterials and Supramolecular Structures. DordrechL the Netherlands Springer, pp. 93-118. 

There are two basic supramolecular structures or morphologies, which correspond to the limiting cases of macromolecular conformation in Fig. 1.6, the random coil model (a) and the modified folding model (e) amorphous morphology and semicrystalline morphology (the word morphology for supermolecular structure was first introduced by A. Keller in the 1960s). 

Varga, J., Crystallisation, Melting and Supramolecular Structure of Isotactic Polypropylene, in Karger-Kocsis, J. (1994), Polypropylene Structure, Blends and Composites, Vol. 1 Structure and Morphology, Chapman Hall, London, pp. 119-139. 

In this chapter, a series of BIN-SMPU supramolecular networks were synthesized from the pyridine derivative and diisocyanate. The structure and morphology of BIN-SMPUs were investigated using a number of techniques, including FT-IR, DSC, WAXD and DMA, and the conclusions drawn can be summarized as follows ... 

In this volume we have collected 10 review chapters from distinguished scientists who have contributed extensively to the study and development of supramolecular assemblies that contain metals and metal-like elements with unusual structures and morphologies and possess potentially useful (and applicable) physical and biological properties. The first chapter by K. Ariga et al. is a general discussion of supramolecular structures that contain inorganic building blocks for hybrid lipid thin films, layer-by-layer assemblies, structure transcription, and functional mesoporous hybrids. This is followed by two chapters, the first by M. L. Kistler et al., who describe the self-assembly of hydrophilic polyoxometalate (POM) macro-anions and examine the structure and behavior of POM macro-ions in solution. This is followed by a chapter by S. K. Das, who provides an overview of the supramolecular features of POM-supported transition metal complexes, POM-crown ether complexes with supramolecular cations, and supramolecular water clusters associated with POMs. 

Therefore, thermodynamic equilibrium of a macroscopic system is an effect of local equilibration processes at a subsystem level (structural hierarchies). In other words, concentration equilibrium in a system (molecular composition equilibrium) doesn t correspond to the equilibrium number and size and especially inner structure (topological) distributions of supramolecular structures and completion of the phase separation process with stationary concentrations in contacting phases doesn t characterize phase solution layering because of possible further coalescence and morphology system changes. All these aspects are evidently stipulated by thermodynamical equilibration kinetics. Further information on equilibration kinetics at various structural organization levels is presented in Parts II and III of this book. 

The model of clusters or ensembles of sites and bonds (secondary supramolecular structure), whose size and structure are determined on the scale of a process under consideration. At this level, the local values of coordination numbers of the lattices of pores and particles, that is, number of bonds per one site, morphology of clusters, etc. are important. Examples of the problems at this level are capillary condensation or, in a general case, distribution of the condensed phase, entered into the porous space with limited filling of the pore volume, intermediate stages of sintering, drying, etc. 

A polymer is considered to be a copolymer when more than one type of repeat unit is present within the chain. There are a variety of copolymers, depending on the relative placement of the different types of repeat units. These are broadly classified as random, block, graft, and alternating copolymers (see Fig. 2.1 for structural details Cheremisinoff 1997 Ravve 2000 Odian 2004). Among these stmctures, block copolymers have attracted particular attention, because of their versatility to form well-defined supramolecular assemblies. When a block copolymer contains two blocks (hydrophobic and hydrophilic), it is called an amphiphilic diblock copolymer. The immiscibility of the hydrophilic and lipophilic blocks in the polymers provides the ability to form a variety of assemblies, the stmctures and morphologies of which can be controlled by tuning the overall molecular weight and molar ratios of the different blocks (Alexandridis et al. 2000). 

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